SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '56f553f36fc5a4436b4014bafda68a912ac469b50f185067ca46f9b8953b40ef' 
  AND token = 'CYrUJ15KzOQwQFOGCQNAwNYz5DYX00MK7hEjdxFUR7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}